echo suppressor

An echo suppressor attempts to determine which is the primary direction and allows that channel to go forward.

This, of course, temporarily defeats the primary effect of having an echo suppressor at all.

In a matter of months, Tellabs began making echo suppressors, which suppress annoying echoes on phone calls.

Trunks using satellite links also had Echo Suppressors connected at their end points.

Hybrids and cancellers are sometimes combined with echo suppressors.

The plain 2100 Hz tone is meant to disable echo suppressors on international trunk connections.

Usually the echo suppressor at the far-end of the circuit adds this loss when it detects voice coming from the near-end of the circuit.

When a sufficient degree of impedance matching is not practical, echo suppressors or echo cancellers, or both, can sometimes reduce the problems.

Echo suppressors work by detecting a voice signal going in one direction on a circuit, and then inserting a great deal of loss in the other direction.

In September 1981, Tellabs introduced the industry's first echo canceller, an advance over the original echo suppressors that synthesized an echo and electronically subtracted it.

Echo cancellers are the replacement for earlier echo suppressors that were initially developed in the 1950s to control echo caused by the long delay on satellite telecommunications circuits.

Echo suppressors were developed in the 1950s in response to the first use of satellites for telecommunications, but they have since been largely supplanted by better performing echo cancellers.

Because each echo suppressor will then detect voice energy coming from the far-end of the circuit, the effect would ordinarily be for loss to be inserted in both directions at once, effectively blocking both parties.

The voice ports used digitally implemented 24kbit/s Delta Modulation with Voice Activity Compression or VAC and Echo Suppressors to control the half second echo path through the satellite.

An echo suppressor or acoustic echo suppressor is a telecommunications device used to reduce the echo heard on long telephone circuits, particularly circuits that traverse satellite links.

Clipping: Since the echo suppressor is alternately inserting and removing loss, there is frequently a small delay when a new speaker begins talking that results in clipping the first syllable from that speaker's speech.

There are cases where both ends are active, and other cases where one end replies faster than an echo suppressor can switch directions to keep the echo attenuated but allow the remote talker to reply without attenuation.

To prevent this, echo suppressors can be set to detect voice activity from the near-end speaker and to fail to insert loss (or insert a smaller loss) when both the near-end speaker and far-end speaker are talking.

If the call is being set up as a voice call between modems, then a 2100 Hz answer tone sent in the backward direction during the initial seconds of the conversation phase of the call will result in any echo cancellers or echo suppressors being disabled for the remainder of the call.